Daniel Sennert’s Evolving Views on Transmutation: an Assortment of Puzzles

Abstract Daniel Sennert’s views on the metallic transmutation promised by alchemy developed over time, shifting from the skeptical position of his earliest writings to a confirmed belief that he acquired by the 1610s. Despite a shrinking pool of empirical support after the publication of his De chymicorum cum Aristotelicis et Galenicis consensu ac dissensu in 1619, the mature Sennert never abandoned his belief in the chrysopoeia or metallic metamorphosis of the alchemists. The present paper explores the reasons for Sennert’s stubborn refusal to reject transmutation even as his developing atomism tacitly rendered it ever less necessary as a tool for explaining material change. The paper also examines Robert Boyle’s critique of Sennert’s atomism as providing an inadequate and perhaps unworkable explanation of chrysopoeia .